Rename folder Docs to docs

2025-08-18 08:30:00 +02:00 · 2023-10-31 11:05:01 +01:00
parent 0915de8f8b
commit 893273739a
900 changed files with 304 additions and 304 deletions
--- a/docs/measure-HeapSort.md
+++ b/docs/measure-HeapSort.md
@@ -0,0 +1,129 @@
+*measure-HeapSort.ps1*
+================
+
+This PowerShell script measures the speed of the HeapSort algorithm.
+HeapSort is a comparison-based sorting algorithm. Heapsort can be thought of as an
+improved selection sort: like selection sort, heapsort divides its input into a sorted
+and an unsorted region, and it iteratively shrinks the unsorted region by extracting
+the largest element from it and inserting it into the sorted region. Unlike selection
+sort, heapsort does not waste time with a linear-time scan of the unsorted region;
+rather, heap sort maintains the unsorted region in a heap data structure to more quickly
+find the largest element in each step.
+
+Parameters
+----------
+```powershell
+PS> ./measure-HeapSort.ps1 [[-numIntegers] <Int32>] [<CommonParameters>]
+
+-numIntegers <Int32>
+    Specifies the number of integers to sort
+    
+    Required?                    false
+    Position?                    1
+    Default value                1000
+    Accept pipeline input?       false
+    Accept wildcard characters?  false
+
+[<CommonParameters>]
+    This script supports the common parameters: Verbose, Debug, ErrorAction, ErrorVariable, WarningAction, 
+    WarningVariable, OutBuffer, PipelineVariable, and OutVariable.
+```
+
+Example
+-------
+```powershell
+PS> ./measure-HeapSort.ps1
+🧭 0.614 sec to sort 1000 integers by HeapSort
+
+```
+
+Notes
+-----
+Author: Markus Fleschutz | License: CC0
+
+Related Links
+-------------
+https://github.com/fleschutz/PowerShell
+
+Script Content
+--------------
+```powershell
+<#
+.SYNOPSIS
+        Measures the speed of HeapSort
+.DESCRIPTION
+        This PowerShell script measures the speed of the HeapSort algorithm.
+        HeapSort is a comparison-based sorting algorithm. Heapsort can be thought of as an
+	improved selection sort: like selection sort, heapsort divides its input into a sorted
+	and an unsorted region, and it iteratively shrinks the unsorted region by extracting
+	the largest element from it and inserting it into the sorted region. Unlike selection
+	sort, heapsort does not waste time with a linear-time scan of the unsorted region;
+	rather, heap sort maintains the unsorted region in a heap data structure to more quickly
+	find the largest element in each step.
+.PARAMETER numIntegers
+        Specifies the number of integers to sort
+.EXAMPLE
+        PS> ./measure-HeapSort.ps1
+        🧭 0.614 sec to sort 1000 integers by HeapSort 
+.LINK
+        https://github.com/fleschutz/PowerShell
+.NOTES
+        Author: Markus Fleschutz | License: CC0
+#>
+
+param([int]$numIntegers = 1000)
+
+class HeapSort {
+    static Sort($targetList) {
+        $heapSize = $targetList.Count
+
+        for ([int]$p = ($heapSize - 1) / 2; $p -ge 0; $p--) {
+            [HeapSort]::MaxHeapify($targetList, $heapSize, $p)
+        }
+
+        for ($i = $targetList.Count - 1; $i -gt 0; $i--) {
+            $temp = $targetList[$i]
+            $targetList[$i] = $targetList[0]
+            $targetList[0] = $temp
+
+            $heapSize--
+            [HeapSort]::MaxHeapify($targetList, $heapSize, 0)
+        }
+    }
+
+    static MaxHeapify($targetList, $heapSize, $index) {
+        $left = ($index + 1) * 2 - 1
+        $right = ($index + 1) * 2
+        $largest = 0
+
+        if ($left -lt $heapSize -and $targetList[$left] -gt $targetList[$index]) {
+            $largest = $left
+        }
+        else {
+            $largest = $index
+        }
+
+        if ($right -lt $heapSize -and $targetList[$right] -gt $targetList[$largest]) {
+            $largest = $right
+        }
+
+        if ($largest -ne $index) {
+            $temp = $targetList[$index]
+            $targetList[$index] = $targetList[$largest]
+            $targetList[$largest] = $temp
+
+            [HeapSort]::MaxHeapify($targetList, $heapSize, $largest)
+        }
+    }
+}
+
+$list = (1..$numIntegers | foreach{Get-Random -minimum 1 -maximum $numIntegers})
+$stopWatch = [system.diagnostics.stopwatch]::startNew()
+[HeapSort]::Sort($list)
+[float]$elapsed = $stopWatch.Elapsed.TotalSeconds
+$elapsed3 = "{0:N3}" -f $elapsed # formatted to 3 decimal places
+"🧭 $elapsed3 sec to sort $numIntegers integers by HeapSort"
+exit 0 # success
+```
+
+*(generated by convert-ps2md.ps1 using the comment-based help of measure-HeapSort.ps1 as of 10/19/2023 08:11:40)*